Non-water Treatment Practices

The majority of the discharge from a desalination processes is concentrated brine from the membrane process, and this may contain quantities of treatment chemicals used. Treatment of water is necessary in all desalination plans for variety of reasons feed water treatment, membrane protection, membrane cleaning, permeate treatment and concentrate treatment prior to discharge. Although non-chemical treatment is possible, chemical treatment is widely practiced. 

Photosynthetic bacteria carry out anoxygenic photosynthesis with organic compounds or reduced sulfur compounds as electron donors. Some non-sulfur photosynthetic bacteria are potent hydrogen producers utilizing organic acids such as lactic, succinic and butyric acids [16]. From practical point of view, photosynthetic bacteria are important since they can be used for dual aims of waste-water treatment and hydrogen production as described in the next section. 

Puckorius Associates, Inc., 1999b. A practical guide to water treatment chemicals. Newsletter., 3 (1). Cooling water systems non-oxidizers -Part 1. 

Health Hazards Information - Recommended Personal Protective Equipment Chemical gloves and eye protection organic vapor canister or self-contained breathing apparatus Symptoms Following Exposure Inhalation of moderate concentrations causes dizziness, drowsiness, and unconsciousness. Contact with eyes or skin may cause irritation the liquid may cause frostbite General Treatment for Exposure INHALATION remove victim to fresh air and apply resuscitation call a physician promptly if victim is unconscious. EYES if irritated, wash with water. SKIN if irritated, wash with soap and water Toxicity by Inhalation (ThresholdUmit Value) 1000 ppm (8 hr) Short-Term Inhalation Limits Data not available Toxicity by Ingestion Not pertinent Late Toxicity None Vapor (Gas) Irritant Characteristics Vapors are non-irritating to eyes and throat Liquid or Solid Irritant Characteristics No appreciable hazard. Practically harmless to the skin because it is very volatile and evaporates quickly. May cause frostbite Odor Threshold Data not available. 

In particular, membrane bioreactors (MBRs) are today robust, simple to operate, and ever more affordable. They take up little space, need modest technical support, and can remove many contaminants in one step. These advantages make it practical, for the first time, to protect public health and safely reuse water for non-potable uses. Membranes can also be a component of a multi-barrier approach to supplement potable water resources. Finally, decentralization, which overcomes some of the sustainability limits of centralized systems, becomes more feasible with membrane treatment. Because membrane processes make sanitation, reuse, and decentralization possible, water sustainability can become an achievable goal for the developed and developing worlds. 

The mineralocorticoid properties of carbenoxolone are probably exerted by displacement of aldosterone from non-specific receptor sites in cells, thus making it more available to affect mineral metabolism. What this means in practice is that in normal doses carbenoxolone can cause salt and water retention, with occasional hypokalemia. These effects are common but usually mUd they are detected more often during treatment if patients are weighed, their blood pressure measured, and serum potassium concentrations checked. Those who take prolonged courses, elderly patients, and those with hepatic, cardiac, or renal impairment are at special risk severe effects, with serious hypertension, heart failure, and hypokalemia of sufficient degree to induce myopathy and tubular necrosis, can usually be ascribed to ill-advised treatment of people in whom carbenoxolone is contraindicated, to its use in elderly patients, or to prolonged intake without supervision. 

---